The Void by Ben Hurst. A Sonic SatAM synopsis by Mark Briggs.
The show opens in a dim canyon of the Great Unknown. The Void, a glowing whirlpool of light, appears to nearly engulf Sonic who manages to escape its pull with a power ring.
Sonic notices a gold object a few feet away. He retrieves it before returning to knothole hoping Sally can figure the object out. From a screen in the Void, the Wizard Naugus notices and wants Sonic's speed and mind.
Sonic arrives in Knothole at Sally's to find her studying with Bunnie. Sonic enters inquiring about his gold object from the Great Unknown. Sally informs him it is from a Giant race called the Mundaran's.
Sonic wonders if it is a fake or created by Robotnik, however, at night when Sally is asleep the gold object activates and carries Sally and Bunnie out of Knothole.
We first hear of the Doomsday when Sonic arrives in Robotropolis to get information from his Uncle Chuck. A flashback occurs where Robotnik is seen sending Wizard Naugus into the Void. Naugus requests removal from the Void by Robotnik in an hour. Robotnik declines so the threat of Naugus returning right now causes him to tighten his security.
Sonic returns to Knothole to find no Sal. He shakes up Nicole to demand where she went. He then heads for the Void in the GU.
Sally meets Naugus in the Void who explains to Sally that despite his magical powers he can't leave. He is a large stout wizard with a lobster claw arm and horn sprouting out of his head.
Outside the Void in the GU, Robotnik follows Sonic to drive him into the Void with Sally and Naugus. Sonic can't handle the assault forced to dives into the whirlpool.
Dissatisfied with Naugus, the FF's leave him to travel further into the Void. In the crystalline place of the Void shines a castle to be gazed at by the FF's.
Inside it the FF's meet the King in bed. Sally is eager to meet her father who tells her he has to leave or he'll die. Sonic uses his speed to transport the King out of the Void.
Bunnie was suspicious but Sonic has already left. In seconds the real King and Ari appear to tell Sally and Bunnie Naugus fooled Sonic to get him out.
Outside the Void again, Naugus transforms Robotnik's head into several animals* as Sonic is instructed by Naugus to save his friends in the Void. Sonic retrieves the other four.
When Sonic returns Naugus wants to play hide and seek with Robotnik to find himself turning to crystal stating he's been in the Void too long.
Naugus, forced back into the void with the King, vows revenge against Robotnik after Sally retrieved a FF's list from her father's pocket.
Back in Knothole, Sonic and Sally talk at Ring Grotto. Sonic finally charms Nicole to take his side against Sally in this case. Scene fades.
*Animal heads: Crow, slug, gorilla, crow again, pig.
Note: This episode prominently features Naugus and the King. It doesn't describe what life in the void is like except Naugus can control a lot of magic in there.